Imaging devices, which are also known as cameras, are used for capturing images of a person, object or scene as desired. They can also be used for ranging, i.e. determining the distance of the person, object or scene from the imaging device.
Modern imaging devices use pixels to capture images. The pixels divide an input image in elements, and capture values for the elements of the image. These values for the image are captured by various techniques, such as numbers of electrons per pixel after a brief exposure time. The output image is typically constructed from the captured values, whether in color or in black and white.